!Fishermen's Guild Member O'Fulle:

Well, I hate to bring this up, but a while back, someone asked me to find a
*Big Yellow Treasure Chest*.
 The bait I gave you earlier was specifically designed to find it!
 Don't look at me like that! It wouldn't have worked if you had known!

I hope it won't be too much trouble for you to find the *Big Yellow Treasure Chest*.
 Use the *bait of chill* to find it. 
You'll find this bait works best when your fishing skill level is exactly 12.
 Someone may have already found it, so you should also ask around in the market.